Drug, or other chemical, delivery with both spatial and temporal control is often difficult with existing technologies. Delivery mechanisms are often either not bio-compatible for long periods of time (such as needles or metal-based implants), not temporally controllable (for proper dosing/delivery, such as pills, patches, etc.), or not targeted spatially (pills, patches, etc.). Providing control over drug delivery can be the most important factor at times when traditional oral or injectable drug formulations cannot be used. This can be due to low therapeutic effect of the drug when administered to the whole patient or that a drug is toxic except at the site where it exerts its action (e.g chemotherapeutic drugs in cancer treatment). Local delivery of drugs is also often needed due to the anatomical and cellular composition of the tissue or organ where adjoining cells should not be subjected to the drug. To achieve maximum control, the drug may need to be administered directly to its site of action, thus there is a need to develop drug delivery systems with spatial and temporal control.
The ideal in vivo drug delivery system should be inert, biocompatible, mechanically strong, comfortable for the patient, capable of achieving high drug loading, safe from accidental release, simple to administer and remove, and easy to fabricate and sterilize. Most contemporary systems meet some of these criteria but not all. Present systems use different methods of achieving in vivo release. Some are based on materials that allow constant passive diffusion of the drug to the tissue. In other systems, where a higher level of control is needed, release can be controlled by a system of micro-valves and pumps. These means of delivery have their disadvantages. Passive release systems lack control and can only allow a constant delivery of the drug. Systems based on micro-valves and pumps usually have the disadvantage that the mechanical parts are sensitive or prone to malfunction. Mechanical release devices are also very expensive due to their delicate components.
There is a need for a system that can be implanted, have strict electronic control over delivery providing high on/off ratios and at the same time allow for local delivery to small specific compartments in the body or even to single cells. The electronic control is crucial as it allows for customized release schedules and most importantly can eventually be coupled to sensors that can activate release upon a certain stimuli or need.
EP 1 862 799 A1, the entire contents of which, is incorporated herein by reference, discloses the general principles of an ion transport device, which is capable of electrically controlled transport of ions from a source electrolyte to a target electrolyte.
Such an ion transport has the spatial and temporal control desired for such a delivery device. However, in its described form, it is not feasible as an implant or as a self-contained device (for example, for use as a “smart-pipette”).
Hence, there is a need for a device for a device and a system that enables delivery of ions in a spatially and temporally controlled manner.